Breeders and the OFA

Progress in hip joint phenotype of dogs in the United States between the 1970's and early 1990's has been shown through results of a retrospective study using the OFA data base. This improvement was evident as an increase in the percentage of dogs classified as having excellent hip joint phenotype and a decrease in the percentage of dogs classified as having hip dysplasia (HD). The increase in percentage of dogs classified as having excellent hip joint phenotype was greater for German Shepherd dogs, Golden Retrievers, Labrador Retrievers, and Rottweiler's than for all dog breeds combined. In addition, the submission screening rate for these four breeds was higher than the screening rate for all dogs. Within these four breeds, the improvement was greatest for Rottweiler's, which also had the highest screening rate.

Overall, low screening rates for breeds found in this study offer some insight into the problems involved with reducing the incidence of HD. The typical dog breeder is involved in breeding dogs for about five years. Thus, informed, experienced breeders are continually replaced with uninformed, inexperienced breeders who may not be as aware of the problems associated with HD or of the importance of participating in a screening program. In addition, many breeders choose which dogs they breed on the basis of the hip phenotype of individual dogs without knowledge of the phenotype of related dogs or previous offspring. It can be very difficult to get hip information on siblings and previous offspring due to the overall low number of dogs radio graphed in a given litter (most dogs in a litter end up in pet homes). This is the slowest method of reducing the incidence of an undesirable trait or increasing the incidence of a desirable trait. The use of preliminary radiographs as early as 4 months of age can be used by breeders to add valuable information on the hip status of dogs they choose to use in a breeding program.